Casing cutter



Feb. 20, 1934. l. J. MCCULLOUGH CASING CUTTER 2 Sheets-Sheet l Filed May 18. 1951 Feb- 20, 1934- l. J. McvcULLouGl-l CAS ING CUTTER Filed May 18, 1951 2 Sheets-Sheet 2 Patented Feb. 20, 1934 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to a well tool, and relates more particularly to a casing cutter for cutting casing, tubing, etc., in a well. It is a general object oi the invention to provide a casing cutter 5 that is dependable and effective in operation and that is particularly simple and easy to operate.

An object of this invention is to provide a casing cutter that includes cutting means for cutting through casing or tubing and a means Vfor indiw eating to the operator that the cutting meansor parts have been actuated to their full out or operative positions.

It is another object of the invention to provide a casing cutter that includes cutters or knives 15 operable to make a clean cut in the casing or tubing that is so shaped that the cutters are easily retractable after making the cut.

It is another object of the invention to provide a casing cutter that includes a casing gripping 2 means for controlling the operation of the cutter that is actuated by fluid pressure. In accordance with the present invention, the pressure of the circulation fluid is employed to automatically operate the casing gripping means prior to actuation of the cutters and to maintain the gripping means in its proper engagement with the casing during operation of the cutters.

lAnother object of the invention is to provide a casing cutter of the character mentioned that n is adjustable so that the cutting parts or knives may be made to cut casing or tubing of different diameters or of different wall thicknesses.

It is another object of the invention to provide a tool of the character mentioned that embodies means for cutting off the circulation of fluid through the operating string upon the knives reaching their fully actuated position to indicate to the operator that the cutters havebeen fully actuated.

A further object of the invention is to provide a casing cutter that may be easily moved through the casing after making a cut to a position to make another cut without dimcult or extensive manipulation of the operating string.

Other objects and features of the invention will be best and more fully understood from the following detailed description of a typical form and application of the invention, throughout which description reference will be had to the accom- 50 panying drawings, in which:

parts in the operating positions.

yand the restricted portion 17 are inclined up- Fig. 1 is a view showing the tool provided by the present invention within a well casingv and carried on the lower end of an operating string. Fig. 2 is an enlarged longitudinal detailed sectional view of the upper portion of the casing cutter illustrating the parts in the unactuatedv position. Fig. 3 is an enlarged longitudinal detailed sectional view of the lower portion of the tool illustrating the parts in the unactuated position. Fig. 4 'is an enlarged longitudinal detailed sectional view of the casing cutter illustrating the Figs. 5 and 6 are enlarged transverse detailed sectional views taken as indicated by lines 5-5 and 6-.6 on Fig. 4. and Fig. 7 is an enlarged side elevation of the lower end portion of the tool.

'I'he tool provided by this inventionv includes, generally, two loosely or slackly connected sections A and B, a releasable connection 10 forA normally holding the sections A and B against relative movement, casing gripping means l1 carried by one of the sections, a hydraulic or fluid pressure actuated means 12 for `operating the lgripping means 11 upon the release of the connection 10, cutters or knives 13 carried by the other section and operable outwardly into engagement with the casing C upon relative movement between the sections A and B, and means 14 for indicating to the operator that the cutters 13 have reached the fully actuated position.

The sections A and B constitute the main or body parts of the tool and are related for relative rotational and longitudinal movement.v The sections A and B have portions telescoped or fitted one into the other,'that is, the section B has a portion extending into the section A. The sectionA A is the upper section of the tool, and is adapted to be attached to an operating string of drill pipe, while the section B is the lower section and eX- tends into the lower end of the section A. 90

The body section A may be provided at its upper end with a socket 15 to receive the screwthreaded pin 16 of a tool joint section, or the like, on the lower end of the operating string S. The section A is tubular, being provided with a central longitudinal opening 17. In the preferred construction, the upper end portion 17a of the body opening is of reduced diameter.v The Walls ofthe opening between its main lower portion wardly and inwardly. A tubular nut 18 is provided on the lower end or" the section A. A pin 19 is provided on the nut 18 and is screw-threaded into the lower' end of the section A. A longitudinal opening 20 is provided in the nut 18 to receive or pass the section B, as will be hereafter described. The nut 18 may be of the same external diameter as the body section A and may be of smaller internal diameter than the section A so that the upper end of the pin 19 forms an upwardly facing shoulder in the lower end of the body opening 17. The body section A is proportioned to pass into the casing C or through the tubing vin which the tool is to operate with suitable clearance. f

The section B is in the nature of an elongated mandrel or stem and is provided to carry the casing gripping means 1l. The section B may bel sectional and may include an upper member .21, a lower member 22, and a block 23 interposed between the members 21 and 22. with the invention, the upper member 21v is tubular and has its lower end attached to the block 23. The lower end of the upper member 21 is screw-threaded into a central longitudinal opening 24 in the block 23. The block 23 may be somewhat wider than the members 21 and 22 and may have 'two diametrically opposite parallel sides 25. The Yopening 24 extends completely through the block, and the upper end of the lower section 22 may be threadedinto its :lower end. The lower section 22 is an elongated cylindrical member and is provided at its lower end with a bull plug or guide plug 26. A vertical socket 27 is providedin the upper end Vof the lower member 22 to forma continuation of the block opening 24.

Means is provided on the lower section B to resist movement relative to the casing C. The means for resisting movement of the section lB through the casing isin the nature of a spring means including longitudinally disposed leaf springs 28. The springs 28 may be arranged at diametrically opposite sides of the section B and may have their upper ends attached tothe upper member 2l and their lower ends attached to the lower member 22. Suitable screws 29 maybe employed to attach the springs 28 to the section B. The springs 28 are bowed outwardly around the block 23 and their intermediater portions are adapted to pressln'ally engage the interior of the casing C.

The releasable connection 10 is provided to hold is'in the nature of ascrew-threaded connectionv that is releasable by relative rotation between the sections A and B. The screw-threaded connection 10 is provided between. the nut 18 and the member 21 and includes a thread on theupper end of the member 21 to co-operate with a thread on the walls of the nut opening 20. The-,connection 10 is adapted to be released upon'rotation of the section A relative vto the section B. The springs 28 operate to hold the section B against rotation during the releasing of the connection 10. After the connection l0 has been released, the section A may be shifted downwardly relative to the section B to cause actuation of the knives or cutters 13.

tively hold the section B against movement during the actuation of the knives 13. It is a feature of the present. invention that the casingl lin accordance gripping means 11 is operable by a fluid pressure actuated means. The gripping means 11 includes dies 30 carried by the block 23 of the lower section B. In the particular embodiment of the invention illustrated in the drawings, there are two like dies 30 carried in diametrically opposite slots31 in the block. The dies 30 are radially shiftable in the slots 31 and have sliding and bearing engagement with the upper and lower ends of the slots, as well as with the side walls of the slots. Gripping parts are provided on the outer ends or faces of the dies 30 to engage or bite into the inner wall of the casing C. The gripping parts 32 of the dies may be in the nature of serrations or teeth shaped to effectively grip the casing C to prevent downward movement of the section B relative to the casing and to readily disengage from the casing upon upward movement ofthe section B. The gripping dies 30 project inwardly into the opening 24 and their inner edges33 are inclined downwardly and inwardly toward the longitudinal axis of the opening.

Means is provided for normally yieldingly holding the grips or dies 30 in retracted positions where they are out of engagement with the casing C. Leaf springs or spring wires 34 are carried by the dies 30 and extend through vertically elongated openings 35 in the dies. The opposite end portions of the springs 34 are slidably carried in openings at the opposite `ends of thel elongated openings or slots 35. Pins 36 are car-V ried by the block 23 and extend horizontally or transversely. through thev openings 35. VThe springs34 are bent or bowed to engage the inner sides of the pins 36 so as to normally urge and yieldingly hold the discs 30 in theretracted positions.

y The iiuid pressure actuated means 12 for moving the dies 30 outwardly tc grip the casing C includes a shaft or stem 37 slidably mountedV in the tubularmember 2l. The stem 37 projects upwardly from the member 21 to extend into the body vopening 17. The stem 37 is adapted to be shifted downwardly through the member 2l and its lower end is shaped to co-operate with the inclined sides 33 of the dies to force the dies outwardly. The lower end portion 38 of the stem 37l is truste-conical or tapered downwardly and inwardly.V The lower end portion 38 of the stem is normally out of engagement with the dies 30, so that the springs 34 may maintain them in retracted positions until actuation of the tool.

. Ahead 39 is mounted on the upper end of the stem 37 within the body opening 17. Ther head 39 is swivelly or rotatably mounted on the stem4 37 and is adapted to be acted upon by the circulation fluid discharging downwardly through the restricted body opening 17a.- A- vertical opening or socket 40 is provided in the lower end of the head toreceive'the upper end rof the stem 37.V Suitable washers 41 may be provided between theupper` end of the stem 37 and the upper end of the opening 40. Means is provided to prevent displacement of the head from the stem. An annular groove 42 is provided in the stem 37, and screws 43 are threaded through openings in the head 39 to extend intol the groove to hold the head against displacement. The head 12 is preferably of round cross sectional configuration, and its lower end portion is prefl erably cylindrical and proportioned to t the The gripping means 1l is provided to posi-V walls. The conical upper portion 440i the headv eiiectively Aacted upon by the fluid 'discharging -Y Areduced' downwardly through the opening 173. guide portion 45 may be provided on the extreme upper end of the head 12V. When the'parts'are in their normal or unactuated positions, the conicharging`4 end of the opening 17EL sec as to be acted upon by the downwardly discharged circulation uid. A plurality of vertical slots 46 are provided in the walls of the body section A.' The slots 46`are provided to carry the knives 13,'as` will be hereinafter described, and operate-to pass or discharge the circulation fluid 'from the opening 17 into the casing'C.

vMeans is provided for normally holding the head 39 and the stem 37 against downward move: ment relative to the body section A. A ring or sleeve 47 is arranged between the lower end of the head 39 and the upper end of the pin'19. The sleeve 47 normally supports the head 39 and its depending stem 37 on the section A. It is to be noted that the section A is rotatable relative to the head 39 and stem 37 and is also free to be shifted downwardly relative to the head 39 upon releasing of the connection 10. The head 39 is not directly connected withv the sectionA, but is only normally supported on -the section A through the sleeve 47 so that it may move independently of the section A after the releasing f of the connection 10. i

The invention includes means for limiting 1ongitudinal movement of the stem 37 relative to the section B. An elongated annular groove o r reduced portion 48 is provided on the stem 37 within the member 21. The uppermost screws 29 and the other like screws 50 are threaded through openings in the member 2l to project intothe groove 48. The screws 29 and v50 are adapted to engage the opposite ends of the groove 48 to limit the longitudinal movement of the stem relative to the section B. The groove 48 is made of suicient length to permit the desired travel of the stem 37 through the member 21.

The knives 13 are pivotally carried by the section A and are operable to cut through the casing C.V The knives 13 are mounted in the slots 46. There may be any suitable number of slots and knives provided in the tool, there being three equally spaced knives in the embodiment illustrated in the drawings. Pins 51 pass transversely through the upper ends of the slots 46 to pivotally carry the cutting blades or knives 13. The body slots 46 occur at the tapered portion of the opening 17, and the lower ends of the cutting knives 13 normally project downwardly andinwardly into the opening 17. The opposite sides of the knives 13 preferably have sliding and bearing engagement with the opposite side walls of the slots 46. The lower edges 52 of the knives may be substantially horizontal when the knives are in the cutting position illustrated in Fig. 4 of the drawings, and may be suitably sharpened to eiectively cut the casing. Pointed projections 53 are provided on the lower ends of the knives.

The upper edges of the projections 53 are in-V clined upwardly and inwardly so that they have suitable 'clearance with the cut made by the cut-l ting edges 52. When the section A is moved downwardly relative to the' head 39, the knives 13 are brought into co-operation with the conical portion 44 of the head so that their lower e thekniv's 13 in the in positions. cal portion 44 ofthe head is out of engagement with the knives 13 and is directly below the dise of 'the knives.

3 of the drawings.

ends aretfedor swung outwardly into-cutting engagement with the casing C. v`

vSpring ineans is provided toV normally yield- Y' ingly'hold the cutting knives 13 in retracted positionsy within the section A; Leaf springs or springl wires 54 are provided to yieldingly hold The upper ends of the-springs' 54 are held invinclined openings 55 in the section A, while the lower ends of the springs extend into openings in the inner edges to normally yhold the lower ends of the knives'13- in positions'where they do not project outward- The springs 54 are bowed so as ly from the'slots 46. 1 The section A- lis intendedv to be rotated during the outward feeding offthe knives 13 so that the vknives make' a circular cut wardly during the actuation of thecutting knives in the casing'C; The section-A is shifted downso that the vknives make a circular cut through' the casing that has upwardly and inwardly inclinedfupper walls. The knives 13 are free to retract or move inwardly from the cut made'in Y this manner upon upward movement of the'section A. y

The means 14 for indicating to the operator that the knives 13 have been fully actuated is operable to cut oiT theilow of circulation fluid through the section A when the knives have `assumed their extreme out positions. A tubular member or nipple 60 is arranged in the restricted opening 17a.

Packing 6l may be' carried by thenipple to seal with the wallsof the opening 17e."

' The lower end ofthe nipple 60 vmay project downwardly into the main body opening' 17, 'and a sealing face or seat 62 Vis provided on its 'lower end to co-operate with thev conical upper end 44 of the head 39. The seat 62 is of the same pitchA or inclination as the conical top of the head so asto eiiectively seal with the head and close off the lower end of the opening 17a. of the seat 62 with the head 39 operates to` limit downwardly movement of the section A relative to the section B and the head 39; and, in accordlilngageinentl ance with the invention, the nipple 60 is adjust-'- able longitudinally in the opening 17a so that the downwardly travel of the section A relative to the section B and the head 39 may be regulated or varied to cause the knives 13 to be fed cutwardly to cut various sizes of casing.

The exterior ofthe nipple 60 is roughened or provided with a plurality of circultr `teeth or threads to bite into the walls of the opening 17a.

Ai set screw 63 is threaded through an opening in the section A to clamp against the nipple 60. The set screw V63 may be employed to releasably set the nipple 60 in any desired position in the opening 17a.' The nipple 60 may be provided With'a flattened part or side to receive the end of the set screw 63. It will be apparent how clamping of the set screw 63 against the nipple causesthe roughened exterior of the nipple to tightly grip the walls of the opening 17e. By

adjusting the nipple 60 longitudinally in the opening 17a, the body section A may be made to have more or less downward movement relative to the head 39 so that the cutting knives 13 may project outwardly from the section A different extents before the sealing face 62 seals with the conical part 44 of the head 39.

In operation, the tool may be lowered through a casing ortubing in the manner Fig. 1 of the drawings, and with the parts in the unactuated positions as illustrated in Figs. 2 and When it is desired to make a cutin the casing "C, the operating string S is rolustrated in tated to release the connection 19. During the releasing or unthreading of the conneet/ionr 10, the body section A moves downwaidgielative .to the section Band the spr-,ings 28 operate .to hold the section B against movement in theca ing, After the connection 10 has been released, he section A may be permitted to settle ornrove .down relative to the section B.. Theoiroulationof. fluid through the drilling string S. is preierahly maintained during` operation of the tool: and, upon the release of the Connection `llt il d discharging through the nipple .60 trikes irnpinges against the conical head, Y39 to force he head and stem 37 downwardly. Downward ting of the vstem 37 brings its tapered lower d 38 into lrio-operation with ythe inner edges 3.3 foi the dies to force the dies outwardly into gripping engagement with the casing In praoe tice, the section A may move downwardly, to: gether with the head V39 and stem V37, un, ti l the stem 37 has reached a position where the dies 30 are in tight gripping eng-agement with the casing, in which position the stem 37 and the head 39 are held against further downward movement. It is to be no-ted that there is no positive connection between the sectionA land the stem 37 by which the stem is Caused `to move do 'ne wardly with the section A so that the gripping means ll is wholly actuated through the action of the fluid on the conical head 3 9 and is actu-k ated before the cutting knives come into engagef ment with the casing. The section Ais otated during its downward movement to feed the `lerrives 13 outwardly so that the knives operate to make an annular or circularcut in the casing C when fed outwardly through their 4engagement v with the conical portion 44 of the head. As the head 39 and the stem 37 are positively held against downward movement by the gripping dies 30 Vdownward shifting of the section A causes the inner and lower corners of the knives 13 to slidably engage the conical portion 4 4 of the head. Engagement by the knives 13 and the conical portion 44 of the head during downward Vfeeding of the section A androtation ofthe section causes the knives 13 to make a dared or outwardly enlarging out in the casing C as they shift or swing radially outward. Upon Vthe knives 13 reaching their predetermined fully out position where they have fully cut through the casing the sealing face 62 of the nipple comes into engagement with .the conical face .4.4 ofi-the head to cut oi the flow of circulation fluid through thev nipple 60. When the yflow of circulation fluid has been stopped in thismanner, the .p urnpSPSsing the fluid into the well labor orstop, and indicate to the operator that the cutters .o r knives 13 have been fully actuated and have cut through the casing.

If it is desired to make another cut in the casing, the pumps are shut Off and 'the operating string S is pulled upwardly, causing the section A to shift upwardly relative to the head30 of the section B. Upon shifting of the section A relative to the head 39 permits the knives -l3 to disengage from the head and be retracted-by the springs 54. As the cut made -by the knives has downwardly and outwardly inclined walls, the knives 13 act to automatically pass inwardly through the slots 46 through their engagement with the walls of the cut. Continued Yupward movement of the section A ybrings `the sleeve 47 into-engagement with the lowerfside ofvtheliead 39 so that the head and stem 3-'7 are Vcausedta move upwardly together with the SBCOIIA, re-

I oonnefetion loagainstthe upper thread inthe itl, ausingthe section. B to move lupwardly together with .the seotion Upon movement ol the stern 37 udessriloeol Vabove raises ,its tapered lower-end out of ,engagement with the dies `30 so that. the dies Yare. free to disengage -rrirorn the WallsA of the easing .and to. .shiftinvvardly- When it is `desi o make the rsecond out in the easing. the. oiY Y. on of fluid 4tinough the string S. ,is resumed dthe string is permitted to settle or lower .somewhat so that the section A mo. .s downwardly.- The aotion of the .oiroulation flu-id the head 39. pauses, the head and thestem 3'7 to move downwardly so that, the dies 30 are again actuated and :the operation of the ,tool may berepeated .as desoriloed above.- Ii it should oe neeessarv to lower `the tool helovv the iirst .out or stony time after .the .oonneotion Y.10 has heen screwed, the oohneetion y may `loe ril-engagedbr holding orpuliingup slightly onfthe seetion A and turning the string rearward to re-thread the oonneotion- Aitor the. connection .10l has heen rerengaged the tool maybe movedto any desired position andoperate vasset forth above- Itis torlie .noted that the ionneotiony 10 need not be reset vfor-eaoli out to be made, as the knives 13 and thsdies 30 automatioallvretraot when the tool is drawn upwardly.` The easing gripping means li is entirely actuated :by the fluid pressure out tuloingv or easing ofvarious diameters and L Wall thiolsnesses- The leasing euttingis partieuf lari-y simple to operate and is very dependable in its operation, as :there is no danger ofthe dies or cutting :knives binding orv sticking in the casing.

Having described only a typical preferred form of the invention, l do not wish to limitfmyself to the specific details set forth', `but wishto reserve to myself all changes and variations that may appear vto those skilled in the art or fall rwithin the scope oi the following Claims:

Having described vrnv invention, I claim:

l. A vtool .for use in a ,easing including, two seotionsrelated vfor relative longitudinal moren ment, means oarried by one section for gripping the casing to hold said section vagainst movement in the-casing whereby the other section may be moved .longitudinally relative to it, a fluid pressure actuated member for operating the said meansand casing cutting means operated by said member upon relative longitudinal movement between lthe sections.

2. A tool for use in a casing including, two sections related for relative movement, a releasable connection for Yholding the sections against relative movement, means carried by one section to hold it against movement in the casing whereby the other `section may be moved relative toit after the release of said connection, -iiuid pressure means for actuating said means, and acutter operable outwardly into engagement with the casing upon relative movement between the secseotionshavingafluid passage, a releasabIe .conf

y4.1i tool for `use in a easing including, two

sections reiated for relative movement, one of the Y sections having a fluid passage, a releasable oonnection or holding the sections against relative movement, means on the other section operable to grip the casing 'to hold said other section sta 115 tionary, uuid pressure actuated means for operan ing the iast mentioned means including a member acted upon by iiuid passing through 'said passage, and a Quitter operable into eiigageifh'eht 'with the casing through cci-operation with said member 20 upon relative movement between the sections.

5. A tool for use .in a easing including, two sections related relative movement, one of the sections having fa vfluidpassage, a releasable connection i" holding Tthe sections against relative efa'hs 'on the other section operable th casihg to hold said other section Sta- A pressure actuated means for operati V lest mentioned means including a member 'acted `upon by fluid passing through .said passage,

(go anun cutter pivotally mounted on the first menioned section operable into engagement with the 'casing through co-operation 'with said member upon relative movement between the sections.

o A tool for use in a casing including, two

g54 L"se'tions related for relative movement, one of the fsections having a fluid passage, a releasable connection for holding 'the sections against relative movement, means 'on the other section operable to grip -'the ceasing to hold said other section sta.-

n ftiona'ry, uuid pressure actuated means for opfrating the last mentioned means including a member acted upon by uid passing through said passe'e, a cutter operable into engagement with the 'casing upon relative movement between the gig ctions, and means for indicating that the cutter has been actuated.

7. A tool for use in a casing including, two vsections related for relative movement, one of the sections having a iiuid passage, a releasable in connection for holding the sections against relative movement, means on the other section operable to fgtip the casing to hold said other secrstationary, uid pressure actuated means for Coperating the last mentioned means includj'ing a member acted upon by iiuid passing Itli-ough said passage, a cutter operable into engagement with the casing upon relative move ment between the sections, and means for indicating that the cutter has been actuated including a part on the rst-mentioned section adapted to engage the said member to close off said passage.

8. A toolfor use in a casing including, two sections related for` relative movement, one of 55 the sections having a huid passage, a releasable connection for holding the sectioh`s against relative movement, means on the other section operable to grip Vthe casing to hold said other section stationary, iiuid pressure actuated means y@ Vfor operating the last mentioned means includ- 'ling a member acted upon by fluid passing vi'jl'l'rough said passage, a cutter carried by the iirst mentioned section operable into engagement with the casing through co-operation with '75 said member upon relative movement between on the other section 'operable VJoy the, lower sectionfor gripping the casing' t0 hold the lower section against movement, a member operable by the fluid in said passage upon 'relative longitudinal movement between the sections, and an operative connection between the member and the die, the cutter being operable through engagement with said member upon relative movement between the seca tions.

l0. A tool for use in a casing including, an upper section having a iiuid passage, a lower`l section. the sections beingrelated for relative movement, a cutter carried by the upper section operable vinto cutting engagement with the casing, a die carried by the lower section for grip-Y ping the easing to hold the lower section against movement, a releasable screw-thread connection between the sections, a member operable downwardly by uid passing through said fluid passage, an operative connection between the member and the die, the cutter being operable byl said member upon downward movement of the upper section, and means for indicating that the cutter has been fully actuated.

11. A tool for use in a casing including, an upper section having a fiuid passage, a lower seca' tion, the sections being related for relative movement, a cutter carried by the upper section op-y erable into cutting engagement with the cas ing, a die carried by the lower section for gripping the casing to hold the lower section against movement, a releasable screw-thread connection between the sections, a member operable downwardly by fluid passing through said fluid passage, an operative connection between the meme, 120 ber and the die, the cutter being operable by" said member upon downward movement of the upper section, and means for indicating that the cutter has been fully actuated, said means including a part carried by the upper section to engage the said member and close the fluid pase sage.

12. A tool for use in a casing including, two sections related for relative longitudinal movement, one of the sections having a fluid passage, means on the other section for gripping the casing, a member operable by huid passing through said `i'iuid passage to actuate said means, a cutter operable outwardly through cooperation with said member upon relative movement between-35 the sections, and a nipple on the rst mentioned section to cooperate with said member and close said fluid passage upon full actuation of the cutter.

13. A tool for use in a casing including twol sections related for relative longitudinal move-'1- ment, one of the sections having a fluid passage, means on the other section for gripping the casing, a member operable by fluid passing through said fluid passage to actuate said means, a cutter operable outwardly through cooperation withsaid member upon relative movement between the sections, the extent of outward actuation of the cutter being dependent upon the amount of relative movement between sections, and a partlw on thefirst mentioned section adapted to cooperate with Ythe ymember to limit relative'longitudinal movement-between" thesections, the said part being adjustable longitudinally of the first -mentioned section whereby the extent of 'actuation of the cutter may be varied.

14. A to'ol for use infa casing including, two sections related or relative longitudinal movement, one of the sections having a uid passage,

means onthe other sectionfor gripping the casing, a'member operable by fluid passing through vsaid' fluid passage to actuate said meansacutter operable loutwardly through ccoperationwith tions, anda nipple screw-threaded to the`first mentioned section operable to engage the member 'to limit relative movement between'the sec:

tion and to close'said'iiuidpassagev l u IRA'J. MCCULLOUGH.

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